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CompletedNCT03998670IXT6Updated Oct 4, 2023Results posted

Base-in Prism Spectacles for Intermittent Exotropia

An interventional study of Prism Glasses and Non-Prism Glasses in Exotropia Intermittent, sponsored by Jaeb Center for Health Research. Completed at 28 sites in United States. Open to participants aged 3 Years to 13 Years. Per ClinicalTrials.gov, last updated 2023-10-04.

Sponsored by Jaeb Center for Health Research · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
61
Allocation
Randomized
Ages
3 Years to 13 Years
Sex
All
01

Study summary

The objective of this short-term, pilot randomized trial comparing spectacles with relieving prism to spectacles without prism is to determine whether to proceed to a full-scale, longer-term randomized trial. This decision will be based primarily on assessing the initial (8-week) response to prism by comparing treatment groups on the following outcomes:

  • Mean distance intermittent exotropia (IXT) control score (the mean of 3 control scores) (primary outcome)
  • The proportion of participants demonstrating a "treatment response," defined as ≥1 point improvement in the mean distance IXT control score without spontaneous exotropia during control testing (secondary outcome)
  • The proportion of participants reporting adverse effects and good/excellent spectacle wear compliance
02

Conditions studied

  • Exotropia Intermittent

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Keywords

  • Prism
03

Who can participate

Ages eligible
3 Years to 13 Years
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

Intermittent Exotropia meeting all of the following criteria:

  • Age 3 to 13 years
  • Mean distance control score of ≥2.00 points with at least 1 measure of 3, 4, or 5 points (i.e, spontaneous tropia) from the 3 assessments during the exam
  • A near control score ≤4 on at least 1 of 3 assessments (cannot have score of 5, 5, 5)
  • Distance exodeviation between 16 Prism Diopters (Δ) and 35 Δ (inclusive) by PACT
  • Near exodeviation between 10 Δ and 35 Δ (inclusive) by PACT
  • Near deviation does not exceed distance deviation by more than 10 Δ by PACT (i.e., convergence insufficiency-type IXT excluded)
  • Refractive error between -6.00 Diopters (D) spherical equivalent (SE) and +2.50 D SE (inclusive) (based on a cycloplegic refraction performed within 7 months but prior to the day of enrollment)
  • Refractive correction (must be worn for at least 1 week if refractive error meets any of the following (based on a cycloplegic refraction performed within 7 months but prior to the day of enrollment):

    • SE anisometropia ≥1.00 D
    • Astigmatism ≥1.00 D in either eye
    • SE myopia ≥-0.50 D in either eye
  • If spectacles have been prescribed and are worn, they must meet the following pre- enrollment criteria:

    • SE anisometropia corrected to within 1.00 D of full SE anisometropic difference
    • Astigmatism corrected to within 1.00 D of full magnitude; axis within 10 degrees if astigmatism ≤1.00 D and axis within 5 degrees if astigmatism >1.00 D

Exclusion criteria

Exclusion Criteria:

  • Dissociated vertical deviation (DVD)
  • Vertical deviation >3 Δ in primary gaze at distance or near
  • Patterns (such as an "A" or "V" pattern) with a downgaze measurement of >10 Δ difference from straight ahead by PACT, measured per investigator's routine method
  • Treatment for IXT or amblyopia (other than refractive correction) within the past 4 weeks, including vision therapy, orthoptics, patching, atropine, or other penalization
  • Substantial overminus spectacles (spectacles overminused by more than 1.00 D SE than the most recent cycloplegic refraction and also results in minus SE power in the spectacles; underplussing is allowed) within the past 4 weeks
  • Prior strabismus, intraocular, or refractive surgery (including BOTOX injection)
  • Previous use of prism spectacles

Additional Eligibility Criteria for Randomization Based on Prism Adaptation Testing

  • Exodeviation by PACT while wearing "trial" relieving prism for 30 minutes is smaller at distance or near than measured during initial testing (e.g. not fully adapting to prism at both distances)
  • No new esotropia on cover test at near while wearing "trial" relieving prism for 30 minutes, compared with enrollment measurement taken without prism
  • No esodeviation >6 Δ on PACT at near while wearing "trial" relieving prism for 30 minutes
04

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Single (Outcomes assessor)
Enrollment
61 participants (actual)

Study arms

  • Experimental
    Prism Group

    Spectacles with refractive correction and base-in relieving prism (40% of the greater of the exodeviation by prism and alternate cover test (PACT) at distance or near) equally divided between the 2 lenses will be prescribed to the participant

    Device: Prism Glasses

  • Placebo comparator
    Non-Prism Group

    Spectacles with refractive correction (or plano spectacles if no significant refractive error) and no prism will be prescribed to the participant

    Device: Non-Prism Glasses

Interventions

  • DevicePrism Glasses

    Spectacles with refractive correction and base-in relieving prism (40% of the greater of the exodeviation by PACT at distance or near) equally divided between the 2 lenses

  • DeviceNon-Prism Glasses

    Spectacles with refractive correction (or plano spectacles if no significant refractive error) and no prism

05

What researchers measure

Primary outcomes

  1. Exotropia Control Score at Distance, Continuous Score

    The primary analysis will be an intent-to-treat comparison of mean 8-week control of the distance exodeviation (average of 3 measurements) between treatment groups using an analysis of covariance (ANCOVA) model, which adjusts for baseline distance control. Distance control scores range from 0 to 5 with higher scores indicating a worse outcome.

    Time frame: 8 weeks

Secondary outcomes

  1. Exotropia Control Score at Distance, % With Treatment Response

    The secondary analysis will calculate the percentage of participants with a "treatment response," defined as ≥1 point improvement in control of their distance exodeviation (average of 3 measurements) between baseline and the 8-week outcome exam.

    Time frame: 8 weeks

  2. Exotropia Control Score at Distance and Near, % With No Spontaneous Tropia

    The proportion of participants with no spontaneous tropia at 8 weeks will be compared between treatment groups using a two-sided Barnard's test with alpha of 0.05, with calculation of a two-sided 95% confidence interval on the difference in proportions. No spontaneous tropia at the 8-week primary outcome exam is defined as a score of ≤2 (0, 1, or 2) on all three assessments of control at distance and at near.

    Time frame: 8 Weeks

  3. Exotropia Control Score at Distance, Continuous Change Between Baseline and 8 Weeks

    Control of the exodeviation was measured at distance using the IXT Office Control Score, (Mohney, 2006) which ranges from 0 (phoria) to 5 (constant exotropia). Control levels 3-5 were assigned based on the duration of manifest exotropia during a 30-second period before any dissociation. If no exotropia was observed, control levels 0-2 were assigned based on the longest time to reestablishing fusion after 3 consecutive 10-second periods of dissociation. Control was measured at the beginning, middle, and end (3 tests) of a 20- to 40-minute office examination, and the mean was used. The change in distance control from baseline to 8 weeks will be calculated. A negative value indicates improvement.

    Time frame: 8 Weeks

  4. Exotropia Control Score at Near, Continuous Score

    Near control will be evaluated similarly to the primary outcome and outcome measures 2-4. Near control scores range from 0 to 5 with higher scores indicating a worse outcome.

    Time frame: 8 Weeks

  5. Exodeviation by PACT at Distance, Continuous

    The measure of ocular alignment at distance by PACT will be summarized at 8 weeks for each treatment group. A higher deviation is worse.

    Time frame: 8 Weeks

  6. Exodeviation by PACT at Near, Continuous

    The measure of ocular alignment at near by PACT will be summarized at 8 weeks for each treatment group. A higher deviation is worse.

    Time frame: 8 Weeks

  7. Randot Preschool Stereoacuity at Near, Continuous

    Randot® Preschool Stereoacuity test (Stereo Optical Co., Inc., Chicago, IL). For analysis, stereoacuity was converted from seconds of arc scores to log arcsec values (in parentheses) as follows: 40 (1.60), 60 (1.78), 100 (2.00), 200 (2.30), 400 (2.60), 800 (2.90); participants with no detectable (nil) stereoacuity were assigned the value of 1600 (3.20). The measure of Randot Preschool Stereoacuity at near will be summarized at 8 weeks for each treatment group. A lower score is better.

    Time frame: 8 Weeks

  8. Compliance of Spectacle Wear

    Parents will be asked to complete a compliance calendar by recording the percentage of time their child has worn the study-prescribed spectacle correction each day. Proportion of time worn each day will be described as excellent (76% to 100%), good (51% to 75%), fair (26% to 50%), poor (1 to 25%), or none (0%). Based on review of the calendars and discussion with parents at the 8-week outcome exam, the investigator will record the total proportion of time worn as excellent (76% to 100%), good (51% to 75%), fair (26% to 50%), poor (1 to 25%), or none (0%: did not fill prescription or never picked up spectacles). The distribution of compliance will be assessed for each treatment group at the outcome exam.

    Time frame: 8 weeks

  9. Child Assessment of Symptoms - Do Your Eyes Hurt?

    Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

    Time frame: 8 Weeks

  10. Child Assessment of Symptoms - Do Your Eyes Feel Funny?

    Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

    Time frame: 8 Weeks

  11. Child Assessment of Symptoms - Do You Have Double Vision?

    Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

    Time frame: 8 Weeks

  12. Child Assessment of Symptoms - Is it Hard for You to Stare at Things?

    Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

    Time frame: 8 Weeks

  13. Child Assessment of Symptoms - Do You Have Problems With Your Eyes in the Sun?

    Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

    Time frame: 8 Weeks

  14. Child Assessment of Symptoms - Do Your Eyes go in and Out?

    Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

    Time frame: 8 Weeks

  15. Child Assessment of Symptoms - Is it Hard to Focus Your Eyes?

    Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

    Time frame: 8 Weeks

  16. Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches?

    Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

    Time frame: 8 Weeks

  17. Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain?

    Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

    Time frame: 8 Weeks

  18. Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close?

    Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

    Time frame: 8 Weeks

  19. Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision?

    Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

    Time frame: 8 Weeks

  20. Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles?

    Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

    Time frame: 8 Weeks

  21. Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Taken His/Her Spectacles Off When he/She Should be Wearing Them?

    Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

    Time frame: 8 Weeks

  22. Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Complained That the Spectacles Hurt His/Her Ears and/or Nose?

    Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

    Time frame: 8 Weeks

Other outcomes

  1. Distance Visual Acuity (Snellen Equivalent)

    Distance visual acuity will be assessed at the 8-week outcome exam. Any optotype method can be used for testing. The distribution of distance visual acuity Snellen Equivalents will be tabulated for each treatment group. A lower Snellen Equivalent is best.

    Time frame: 8 Weeks

  2. Fusional Convergence - Continuous Break Point

    As an exploratory analysis, the distribution of fusional convergence amplitude (break point, blur point, and recovery) at 8 weeks will be summarized for each treatment group. Fusional amplitudes are a measure of how well a participant can converge their eyes using fusional vergence. It is measured by increasing base-out prism to the point that the participant is no longer able to control the deviation. The total amount of fusion is the magnitude of the base-out prism the participant was able to overcome plus the magnitude of the deviation. A higher number of prism diopters for break point is better than a lower number. A lower number for recovery point is better than a higher number.

    Time frame: 8 Weeks

  3. Suppression

    The suppression assessment is a standardized method of assessing the depth of suppression experienced while the participant is tropic (NOT aligned). Scoring is reported on an ordinal scale from 0 (no suppression) to 3 (dense suppression). "Missing" refers to cases in which participants were unable to understand the test and/or gave unreliable responses. As an exploratory analysis, the distribution of suppression level (none, mild, moderate, severe, missing) will be tabulated after 8 weeks by treatment group.

    Time frame: 8 Weeks

  4. Fusional Convergence - Continuous Recovery Point

    As an exploratory analysis, the distribution of fusional convergence amplitude (break point, blur point, and recovery) at 8 weeks will be summarized for each treatment group. Fusional amplitudes are a measure of how well a participant can converge their eyes using fusional vergence. It is measured by increasing base-out prism to the point that the participant is no longer able to control the deviation. The total amount of fusion is the magnitude of the base-out prism the participant was able to overcome plus the magnitude of the deviation. A higher number of prism diopters for break point is better than a lower number. A lower number for recovery is better than a higher number.

    Time frame: 8 Weeks

06

Results

Posted Oct 17, 2022

Participant flow

Between 09/01/2019 and 07/30/2020, 61 participants were enrolled into the study across 28 clinical sites. After prism-adaptation testing to confirm eligibility, 4 participants did not meet eligibility criteria and 57 participants were randomized to receive either 40% base-in prism spectacles (n=28) or non-prism spectacles (n=29).

Participant flow — Overall Study
MilestonePrism GroupNon-Prism Group
Started2829
Completed2525
Not completed34

Outcome measures

PrimaryExotropia Control Score at Distance, Continuous Score

The primary analysis will be an intent-to-treat comparison of mean 8-week control of the distance exodeviation (average of 3 measurements) between treatment groups using an analysis of covariance (ANCOVA) model, which adjusts for baseline distance control. Distance control scores range from 0 to 5 with higher scores indicating a worse outcome.

Time frame:
8 weeks
Reported as:
Mean · units on a scale
Exotropia Control Score at Distance, Continuous Score
units on a scalePrism GroupNon-Prism Group
Exotropia Control Score at Distance, Continuous Score3.6 ± 1.33.3 ± 1.5
Statistical analysis
  • Prism Group vs Non-Prism Group · Mean difference (final values): 0.3 · 95% CI -0.5 to 1.1Difference in mean control and 95% confidence interval (CI) are from ANCOVA model adjusting for corresponding baseline control score. Prism group minus Non-Prism group (positive difference indicates Prism group worse than Non-Prism group).
SecondaryExotropia Control Score at Distance, % With Treatment Response

The secondary analysis will calculate the percentage of participants with a "treatment response," defined as ≥1 point improvement in control of their distance exodeviation (average of 3 measurements) between baseline and the 8-week outcome exam.

Time frame:
8 weeks
Reported as:
Number · percentage of participants
Exotropia Control Score at Distance, % With Treatment Response
percentage of participantsPrism GroupNon-Prism Group
Exotropia Control Score at Distance, % With Treatment Response3224
Statistical analysis
  • Prism Group vs Non-Prism Group · Mean difference (final values): 8 · 95% CI -17 to 32Difference between Prism minus Non-Prism group (positive difference indicates Prism group better than Non-Prism group).
SecondaryExotropia Control Score at Distance and Near, % With No Spontaneous Tropia

The proportion of participants with no spontaneous tropia at 8 weeks will be compared between treatment groups using a two-sided Barnard's test with alpha of 0.05, with calculation of a two-sided 95% confidence interval on the difference in proportions. No spontaneous tropia at the 8-week primary outcome exam is defined as a score of ≤2 (0, 1, or 2) on all three assessments of control at distance and at near.

Time frame:
8 Weeks
Reported as:
Number · percentage of participants
Exotropia Control Score at Distance and Near, % With No Spontaneous Tropia
percentage of participantsPrism GroupNon-Prism Group
Exotropia Control Score at Distance and Near, % With No Spontaneous Tropia4851
Statistical analysis
  • Prism Group vs Non-Prism Group · Mean difference (final values): -4 · 95% CI -27 to 19Difference between Prism minus Non-Prism group (positive difference indicates Prism group better than Non-Prism group).
SecondaryExotropia Control Score at Distance, Continuous Change Between Baseline and 8 Weeks

Control of the exodeviation was measured at distance using the IXT Office Control Score, (Mohney, 2006) which ranges from 0 (phoria) to 5 (constant exotropia). Control levels 3-5 were assigned based on the duration of manifest exotropia during a 30-second period before any dissociation. If no exotropia was observed, control levels 0-2 were assigned based on the longest time to reestablishing fusion after 3 consecutive 10-second periods of dissociation. Control was measured at the beginning, middle, and end (3 tests) of a 20- to 40-minute office examination, and the mean was used. The change in distance control from baseline to 8 weeks will be calculated. A negative value indicates improvement.

Time frame:
8 Weeks
Reported as:
Mean · units on a scale
Exotropia Control Score at Distance, Continuous Change Between Baseline and 8 Weeks
units on a scalePrism GroupNon-Prism Group
Exotropia Control Score at Distance, Continuous Change Between Baseline and 8 Weeks0.1 ± 1.4-0.2 ± 1.5
SecondaryExotropia Control Score at Near, Continuous Score

Near control will be evaluated similarly to the primary outcome and outcome measures 2-4. Near control scores range from 0 to 5 with higher scores indicating a worse outcome.

Time frame:
8 Weeks
Reported as:
Mean · units on a scale
Exotropia Control Score at Near, Continuous Score
units on a scalePrism GroupNon-Prism Group
Exotropia Control Score at Near, Continuous Score1.7 ± 1.11.7 ± 1.3
Statistical analysis
  • Prism Group vs Non-Prism Group · Mean difference (final values): 0.01 · 95% CI -0.7 to 0.7Difference in mean control and 95% confidence interval (CI) are from ANCOVA model adjusting for corresponding baseline control score. Prism group minus Non-Prism group (positive difference indicates Prism group worse than Non-Prism group).
SecondaryExodeviation by PACT at Distance, Continuous

The measure of ocular alignment at distance by PACT will be summarized at 8 weeks for each treatment group. A higher deviation is worse.

Time frame:
8 Weeks
Reported as:
Mean · prism diopters
Exodeviation by PACT at Distance, Continuous
prism dioptersPrism GroupNon-Prism Group
Exodeviation by PACT at Distance, Continuous30.6 ± 9.326.5 ± 8.1
SecondaryExodeviation by PACT at Near, Continuous

The measure of ocular alignment at near by PACT will be summarized at 8 weeks for each treatment group. A higher deviation is worse.

Time frame:
8 Weeks
Reported as:
Mean · prism diopters
Exodeviation by PACT at Near, Continuous
prism dioptersPrism GroupNon-Prism Group
Exodeviation by PACT at Near, Continuous28.7 ± 8.219.0 ± 9.8
SecondaryRandot Preschool Stereoacuity at Near, Continuous

Randot® Preschool Stereoacuity test (Stereo Optical Co., Inc., Chicago, IL). For analysis, stereoacuity was converted from seconds of arc scores to log arcsec values (in parentheses) as follows: 40 (1.60), 60 (1.78), 100 (2.00), 200 (2.30), 400 (2.60), 800 (2.90); participants with no detectable (nil) stereoacuity were assigned the value of 1600 (3.20). The measure of Randot Preschool Stereoacuity at near will be summarized at 8 weeks for each treatment group. A lower score is better.

Time frame:
8 Weeks
Reported as:
Mean · log arc seconds
Randot Preschool Stereoacuity at Near, Continuous
log arc secondsPrism GroupNon-Prism Group
Randot Preschool Stereoacuity at Near, Continuous2.2 ± 0.41.9 ± 0.4
SecondaryCompliance of Spectacle Wear

Parents will be asked to complete a compliance calendar by recording the percentage of time their child has worn the study-prescribed spectacle correction each day. Proportion of time worn each day will be described as excellent (76% to 100%), good (51% to 75%), fair (26% to 50%), poor (1 to 25%), or none (0%). Based on review of the calendars and discussion with parents at the 8-week outcome exam, the investigator will record the total proportion of time worn as excellent (76% to 100%), good (51% to 75%), fair (26% to 50%), poor (1 to 25%), or none (0%: did not fill prescription or never picked up spectacles). The distribution of compliance will be assessed for each treatment group at the outcome exam.

Time frame:
8 weeks
Reported as:
Count of participants · Participants
Compliance of Spectacle Wear
ParticipantsPrism GroupNon-Prism Group
Excellent (76% to 100%)2222
Good (51% to 75%)32
Fair (26% to 50%)01
Poor (1% to 25%)00
None (0%)00
SecondaryChild Assessment of Symptoms - Do Your Eyes Hurt?

Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

Time frame:
8 Weeks
Reported as:
Count of participants · Participants
Child Assessment of Symptoms - Do Your Eyes Hurt?
ParticipantsPrism GroupNon-Prism Group
Never1522
Sometimes63
Almost Always40
SecondaryChild Assessment of Symptoms - Do Your Eyes Feel Funny?

Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

Time frame:
8 Weeks
Reported as:
Count of participants · Participants
Child Assessment of Symptoms - Do Your Eyes Feel Funny?
ParticipantsPrism GroupNon-Prism Group
Never1720
Sometimes73
Almost Always12
SecondaryChild Assessment of Symptoms - Do You Have Double Vision?

Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

Time frame:
8 Weeks
Reported as:
Count of participants · Participants
Child Assessment of Symptoms - Do You Have Double Vision?
ParticipantsPrism GroupNon-Prism Group
Never1717
Sometimes87
Almost Always01
SecondaryChild Assessment of Symptoms - Is it Hard for You to Stare at Things?

Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

Time frame:
8 Weeks
Reported as:
Count of participants · Participants
Child Assessment of Symptoms - Is it Hard for You to Stare at Things?
ParticipantsPrism GroupNon-Prism Group
Never1615
Sometimes78
Almost Always22
SecondaryChild Assessment of Symptoms - Do You Have Problems With Your Eyes in the Sun?

Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

Time frame:
8 Weeks
Reported as:
Count of participants · Participants
Child Assessment of Symptoms - Do You Have Problems With Your Eyes in the Sun?
ParticipantsPrism GroupNon-Prism Group
Never1114
Sometimes85
Almost Always66
SecondaryChild Assessment of Symptoms - Do Your Eyes go in and Out?

Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

Time frame:
8 Weeks
Reported as:
Count of participants · Participants
Child Assessment of Symptoms - Do Your Eyes go in and Out?
ParticipantsPrism GroupNon-Prism Group
Never2019
Sometimes23
Almost Always33
SecondaryChild Assessment of Symptoms - Is it Hard to Focus Your Eyes?

Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

Time frame:
8 Weeks
Reported as:
Count of participants · Participants
Child Assessment of Symptoms - Is it Hard to Focus Your Eyes?
ParticipantsPrism GroupNon-Prism Group
Never1612
Sometimes511
Almost Always42
SecondaryParent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches?

Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

Time frame:
8 Weeks
Reported as:
Count of participants · Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches?
ParticipantsPrism GroupNon-Prism Group
Never1514
Almost Never86
Sometimes25
Often00
Almost Always00
SecondaryParent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain?

Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

Time frame:
8 Weeks
Reported as:
Count of participants · Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain?
ParticipantsPrism GroupNon-Prism Group
Never1611
Almost Never54
Sometimes49
Often01
Almost Always00
SecondaryParent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close?

Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

Time frame:
8 Weeks
Reported as:
Count of participants · Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close?
ParticipantsPrism GroupNon-Prism Group
Never2215
Almost Never26
Sometimes03
Often11
Almost Always00
SecondaryParent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision?

Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

Time frame:
8 Weeks
Reported as:
Count of participants · Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision?
ParticipantsPrism GroupNon-Prism Group
Never2121
Almost Never23
Sometimes11
Often10
Almost Always00
SecondaryParent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles?

Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

Time frame:
8 Weeks
Reported as:
Count of participants · Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles?
ParticipantsPrism GroupNon-Prism Group
Never1214
Almost Never73
Sometimes55
Often03
Almost Always10
SecondaryParent Assessment of Symptoms and Spectacle Wear - Has Your Child Taken His/Her Spectacles Off When he/She Should be Wearing Them?

Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

Time frame:
8 Weeks
Reported as:
Count of participants · Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Taken His/Her Spectacles Off When he/She Should be Wearing Them?
ParticipantsPrism GroupNon-Prism Group
Never510
Almost Never115
Sometimes68
Often31
Almost Always01
SecondaryParent Assessment of Symptoms and Spectacle Wear - Has Your Child Complained That the Spectacles Hurt His/Her Ears and/or Nose?

Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.

Time frame:
8 Weeks
Reported as:
Count of participants · Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Complained That the Spectacles Hurt His/Her Ears and/or Nose?
ParticipantsPrism GroupNon-Prism Group
Never1714
Almost Never35
Sometimes55
Often01
Almost Always00
Other pre-specifiedDistance Visual Acuity (Snellen Equivalent)

Distance visual acuity will be assessed at the 8-week outcome exam. Any optotype method can be used for testing. The distribution of distance visual acuity Snellen Equivalents will be tabulated for each treatment group. A lower Snellen Equivalent is best.

Time frame:
8 Weeks
Reported as:
Count of participants · Participants
Distance Visual Acuity (Snellen Equivalent)
ParticipantsPrism GroupNon-Prism Group
20/16 (best)31
20/20109
20/2598
20/3223
20/4014
Other pre-specifiedFusional Convergence - Continuous Break Point

As an exploratory analysis, the distribution of fusional convergence amplitude (break point, blur point, and recovery) at 8 weeks will be summarized for each treatment group. Fusional amplitudes are a measure of how well a participant can converge their eyes using fusional vergence. It is measured by increasing base-out prism to the point that the participant is no longer able to control the deviation. The total amount of fusion is the magnitude of the base-out prism the participant was able to overcome plus the magnitude of the deviation. A higher number of prism diopters for break point is better than a lower number. A lower number for recovery point is better than a higher number.

Time frame:
8 Weeks
Reported as:
Mean · prism diopters
Fusional Convergence - Continuous Break Point
prism dioptersPrism GroupNon-Prism Group
Fusional Convergence - Continuous Break Point17.8 ± 11.517.5 ± 10.9
Other pre-specifiedSuppression

The suppression assessment is a standardized method of assessing the depth of suppression experienced while the participant is tropic (NOT aligned). Scoring is reported on an ordinal scale from 0 (no suppression) to 3 (dense suppression). "Missing" refers to cases in which participants were unable to understand the test and/or gave unreliable responses. As an exploratory analysis, the distribution of suppression level (none, mild, moderate, severe, missing) will be tabulated after 8 weeks by treatment group.

Time frame:
8 Weeks
Reported as:
Count of participants · Participants
Suppression
ParticipantsPrism GroupNon-Prism Group
None (0 suppression)15
Mild (1 suppression)53
Moderate (2 suppression)64
Dense (3 suppression)1210
Missing13
Other pre-specifiedFusional Convergence - Continuous Recovery Point

As an exploratory analysis, the distribution of fusional convergence amplitude (break point, blur point, and recovery) at 8 weeks will be summarized for each treatment group. Fusional amplitudes are a measure of how well a participant can converge their eyes using fusional vergence. It is measured by increasing base-out prism to the point that the participant is no longer able to control the deviation. The total amount of fusion is the magnitude of the base-out prism the participant was able to overcome plus the magnitude of the deviation. A higher number of prism diopters for break point is better than a lower number. A lower number for recovery is better than a higher number.

Time frame:
8 Weeks
Reported as:
Mean · prism diopters
Fusional Convergence - Continuous Recovery Point
prism dioptersPrism GroupNon-Prism Group
Fusional Convergence - Continuous Recovery Point9.4 ± 10.110.6 ± 9.4

Adverse events

Collected over Adverse events were monitored/assessed from the participant's perspective between randomization and completion of their 8-week primary outcome visit.. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
Prism Group0/28 (0%)0/28 (0%)0/28 (0%)
Non-Prism Group0/29 (0%)0/29 (0%)0/29 (0%)

Baseline characteristics

Age, Categorical
Age, Categorical(Participants)Prism GroupNon-Prism GroupTotal
<=18 years282957
Between 18 and 65 years000
>=65 years000
Age, Continuous
Age, Continuous(years)Prism GroupNon-Prism GroupTotal
Mean6.4 ± 2.46.8 ± 2.16.6 ± 2.2
Age, Customized
Age, Customized(Participants)Prism GroupNon-Prism GroupTotal
3 to <5 years10717
5 to <7 years71017
7 to <9 years8816
>=9 years347
Sex: Female, Male
Sex: Female, Male(Participants)Prism GroupNon-Prism GroupTotal
Female171633
Male111324
Race/Ethnicity, Customized
Race/Ethnicity, Customized(Participants)Prism GroupNon-Prism GroupTotal
Asian033
Black/African American628
Hispanic4711
White161733
More than one race202
Region of Enrollment
Region of Enrollment(participants)Prism GroupNon-Prism GroupTotal
United States282957
Refractive Error Average of Eyes, Continuous
Refractive Error Average of Eyes, Continuous(Spherical Equivalent Diopters)Prism GroupNon-Prism GroupTotal
Mean0.3 ± 1.00.1 ± 1.40.2 ± 1.2
Refractive Error Average of Eyes, Categorical
Refractive Error Average of Eyes, Categorical(Participants)Prism GroupNon-Prism GroupTotal
-6.00 to <-2.00 diopters134
-2.00 to <-1.00 diopters202
-1.00 to <-0.00 diopters448
0.00 to <1.00 diopters121628
1.00 to <2.00 diopters9615

12 further baseline measures are reported on the registry.

07

Study locations

28 sites
  • UAB Pediatric Eye Care; Birmingham Health Care
    Birmingham, Alabama 35294, United States
  • Midwestern University Eye Institute
    Glendale, Arizona 85308, United States
  • Arkansas Childrens
    Little Rock, Arkansas 72202, United States
  • Southern California College of Optometry
    Fullerton, California 92831-1699, United States
  • Western University College of Optometry
    Pomona, California 91766, United States
  • Nova Southeastern University College of Optometry, The Eye Institute
    Fort Lauderdale, Florida 33382, United States
  • Ann & Robert H. Lurie Children's Hospital of Chicago
    Chicago, Illinois 60611, United States
  • Illinois College of Optometry
    Chicago, Illinois 60616, United States
  • University of Chicago
    Hyde Park, Illinois 60637, United States
  • Indiana School of Optometry
    Bloomington, Indiana 47405, United States
  • Indiana University School of Optometry
    Indianapolis, Indiana 47405, United States
  • Wolfe Eye Clinic
    West Des Moines, Iowa 50266, United States
  • University of Kentucky Department of Neurology
    Lexington, Kentucky 40536, United States
  • Wilmer Eye Institute
    Baltimore, Maryland 21287-9028, United States
  • Boston Medical Center
    Boston, Massachusetts 02118, United States
  • Boston Children's Hospital Waltham
    Boston, Massachusetts 02453, United States
  • Pediatric Ophthalmology, P.C.
    Grand Rapids, Michigan 49546, United States
  • University of Nebraska Medical Center
    Omaha, Nebraska 68114, United States
  • Cincinnati Children's Hospital
    Cincinnati, Ohio 45229, United States
  • Ohio State University College of Optometry
    Columbus, Ohio 43210-1280, United States
  • OHSU Casey Eye Institute
    Portland, Oregon 97239, United States
  • Pediatric Ophthalmology of Erie
    Erie, Pennsylvania 16501, United States
  • Salus University/Pennsylvania College of Optometry
    Philadelphia, Pennsylvania 19141, United States
  • Vanderbilt University Medical Center
    Nashville, Tennessee 37232, United States
  • Texas Children's Hospital - Dept. Of Ophthalmology
    Houston, Texas 77030, United States
  • Houston Eye Associates
    The Woodlands, Texas 77381, United States
  • Virginia Pediatric Eye Center
    Norfolk, Virginia 23502, United States
  • Gundersen Health System
    La Crosse, Wisconsin 54601, United States
08

References and documents

Publications

  • Summers AI, Morrison DG, Chandler DL, Henderson RJ, Chen AM, Leske DA, Walker KR, Li Z, Melia BM, Bitner DP, Kurup SP, Allen M, Phillips PH, Nash DL, Grigorian AP, Kraus CL, Miller AM, Titelbaum JR, Kraker RT, Holmes JM, Cotter SA; Pediatric Eye Disease Investigator Group. A Pilot Randomized Clinical Trial of Base-in Relieving Prism Spectacle Treatment of Intermittent Exotropia. Optom Vis Sci. 2023 Jul 1;100(7):432-443. doi: 10.1097/OPX.0000000000002039. Epub 2023 Jul 1. PubMed 37399233 ↗
  • Hatt SR, Leske DA, Holmes JM, Henderson RJ, Chandler DL, Morrison DG, Summers AI, Cotter SA. Testing depth of suppression in childhood intermittent exotropia. J AAPOS. 2022 Feb;26(1):36-38.e1. doi: 10.1016/j.jaapos.2021.08.303. Epub 2021 Nov 16. PubMed 34793970 ↗

Study documents

  • Study protocol · May 29, 2019
  • Statistical analysis plan · Apr 15, 2020
  • Informed consent form · Jun 18, 2019

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: Yes — In accordance with the NIH data sharing policy, a de-identified database is placed in the public domain on the Pediatric Eye Disease Investigator Group (PEDIG) public website after the completion of each protocol and publication of the primary manuscript.

Supporting information: Study protocol, Sap, Icf

09

Registry details

Key details

Study ID
NCT03998670
Lead sponsor
Jaeb Center for Health Research
Collaborators
Pediatric Eye Disease Investigator Group, National Eye Institute (NEI)
Responsible party
Sponsor
First posted
Jun 26, 2019
Start date
Sep 1, 2019
Primary completion
Jul 30, 2020
Completion
Jul 30, 2020
Results posted
Oct 17, 2022
Last update
Oct 4, 2023

Study contacts

David G Morrison, MD
study chair · Vanderbilt University Medical Center
Allison I Summers, OD, MCR
study chair · Oregon Health and Science University

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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